Refrigerating system



June 23,1942. HA, B, BROW 2,287,492

REFRIGERATING SYSTEM File d May 27, 1940 2 sheets-sheet 1 INVENTOR 5 HHEEY H-B' BROWN ATTORNEYj June 23, 1942.

H. A. B. BROWN 2,287,492

REFRIGERATING SYSTEM Filed May 27, 1940 2 Sheets-Sheet 2 INVENTOR H1422) 44B. BROWN BY M,

ATTORN EY5 .ina

Patented June 23, 1942 p UNITED. STATES PATENT OFFICE REFRIGERATING SYSTEM Harry B. Brown, Pittsburgh, Pa. Application May 27, 1940, Serial No. 337,464 e11 62-915) Claims.

ciently controlling the temperature in the area to be cooled.

Other objects and advantages .will appear in the description and drawings annexed hereto.

In the drawings Fig. .1 is a schematic view of the refrigerating system.

Fig. 2 is an enlarged sectional view of the 'main system as described above for more efiifunction during the movement ofthe car as well as during periods when the car is stationary, or on a siding.

In actual practice, I have found that a control means in a refrigerating system that is'subjected to the abuse and lack of constant attention, such as occurs in refrigerator cars, should be substancontrol valve in the refrigerating system, with part of the tank to which it is attached being shown.

Fig. 3 is a semi-diagrammatic view of the refrigerating system in a refrigerator car.

Fig. ,4 is a sectional view as seen from line 3-4 of Fig. 3.

'Fig. 5 is an enlarged cross-sectional view of one of the cooling elements in position along one corner of a room or car.

Fig. 6 is an enlarged'fragmentary sectional view of a portion of the element shown in Fig. 5.

Fig. 7 is a reduced sectional view of a portion corresponding to that of Fig. 6, but showing a different shape of conduit.

Fig. 8 is a reduced plan view of one of the cooling elements to indicate the inlet and outlet thereto.

The system, as described hereafter, is an improvement of the invention described in .my copending application, Ser. No. 271,052, filed May In refrigerator cars, or vehicles, one-of the a partial or total loss. While moving from its point of origin to its destination the car is subjected to appreciable vibration and rocking. Therefrigerating system, however, must continue to tially independent of spring power, or have an electrical or mechanical motor for its successful operation. Springs are too readily broken, and are too variable in operation to be suiiiciently dependable. Mercury controlled systems have been contemplated, but the tendency of mercury to become displaced during rolling of the car when in movement is not satisfactory. Also mercury is susceptible to appreciable changes in volume during temperature changes, and is liable to leak.

The foregoing objections have been overcome in this invention by eliminating springs and by other arrangements.

In Fig. 1 I show a tank I for solid CO2, also known as dry ice," designated 2, which tank is formed with ,an inner bottom 3 and side walls 4 at its lower end, forming an enclosed chamber 5 between the inner tank and side walls, and the bottom and sides of the main tank. The upper edges of sides 'il connect with the sides of tank I, as at 6. Between the sides ofthe tank and wall 4, is a helically shaped spacer 1 commencing at one end near to, but spaced slightly from the upper end 6 of the chamber 5 and terminating adjacent the space between the double bottom, thus forming a helically shaped passage around the walls 3. At the upper end of tank I is an opening provided with a tight,.removable closure 8 for filling the tank with the solid C02, and a pressure relief valve 9 is also provided at the upper end of the tank for maintaining the gas within the tank at a predetermined pressure of say, about 6 or 8 pounds.

- The main control apparatus for causing circulation of a liquid refrigerant (later to be deprincipal disadvantages heretofore has been the Y scribed) is a relatively small tank Hi provided with a horizontal partition ll dividing the interior of the tank into an upper chamber l2 and a lower chamber It. This tank is preferably cylindrical and vertically disposed, and centrally in the upper head It, thereof, is a control device I5, while a vertical tube I6 extends downwardly from the partition II to adjacent the lower end of the bottom IS, the upper end of said tube extending through the partitionand opening into the chamber l2, while'a check valve "at the lower end of said tube (the purpose of which will with the recess formed but preventing the chamber 5 that is at of liquid from valve is closed. As the diameter of the valve 33 I is less than the diameter of chamber 35, when the valve 33 ismoved vertically from-its seat, there is a free communication between the'conduit 28, chamber 35 and chamber 36.

Below the restricted diameter length 28 of the bore through body 28, the said bore is uniformly enlarged at 38 for a substantial distance, which enlarged portion 38 terminates at its lower end in a still further enlarged portion 33. The shoulder at the juncture between said portions 38,

the lower end of tank I, a pipe 28 extends to the inlet end of a. cooling coil 2i, the outlet end of a said coil communicating with the lower portion of chamber l2 .by a pipe 22. In said pipe 22, adjacent said coil, is a thermostatically actuated valve 23 connected with a-thermostat 24, such as a sylphon, the latter being disposed in the area to be cooled by heat transfer to said coil When a desired lowered temperature is reached in said area, the thermostat 24 will cause the valve 23 to close, while a rise in the temperature will result in actuation of the valve to open the same. The tube Ii, chamber l3, pipe l8, chamber 5 (including helical passageway), pipe 28, coil 2|, pipe 22 and chamber l2, form a closed circuit for a liquid refrigerant 25,

,indicated in chamber l3. The normal flow of such refrigerant is in the direction of the arrows, from chamber 13 back to chamber l2, after passage through the chamber 5 and cooling coil 2|.

However, there can be no such flow, valve 23 is open.

A conduit 25 for gas communicates between the device l5 and the upper end of chamber l3, while a branch 21 extends. from said conduit to the upper end of tank I. By this arrangement it will be seen that the liquid in chamber l3 will always be subjected to gas under pressure from tank I, while a gas pressure line carrying gas under the same pressure will lead to device I5.

Since the device l5 and the elements directly associated therewith is an important feature or this invention, the same is shown-in detail in unless the Fig. 2. This device comprises a vertically exits uppertending body 28 externally threaded at and lower ends and formed with a central openended cylindrical boretherothrough coaxial with the longitudinal axis of the body. The upper most end of said bore progressively enlarged upwardly from a restricted diameter length 23 of the bore, such enlarged'portions being concentric with the central axis of the portion 23. These enlarged portions, commencing with the upper 'end or the portion 28, are designated 38, 3|,

32, .there being shoulders between adjacent portions, and'the shoulder between portions 3|, 32 is beveled to form a conical valve seat for seating the correspondingly tapered lower side of a disk-like valve element 33.

A cap 34 is threadedlysecured to the threads at the upper end ofbody 28, the top of which is interiorly 'to correspond to the uppermost enlargement 32 of the bore that extends I tln'oughsaid may 2:.

One end of conduit 25 is secured in a central aperture in the top of said cap, communicating in the under side thereof, and the sides of enlarged portion 32 coacts with said recess to form a chamber 35 above disk valve 33, while the sides of enlarged portion 38 in cooperation with the valve forms a chamber 35 below said valve, which latter chamber is separated from the chamber35 by the valve 33 when the 38 is beveled to form a conical seat for the correspondingly tapered upper and, outer edge of a cylindrical, vertically extending valve'memb'er 48.

The valve 33 and valve member 48 are connected by a stem 4| that is secured at one end to valve 33 and threaded into a central bore 42 extending through the member 48.- This stem is nicely I fitted in the portion 29 of the bore through body 28 for sliding longitudinally, and to prevent escape of gas past the stem and portion 28.

The lower threaded end, of the body 28 is threadedly secured into an aperture in the upper 7 end 14 of the tank l8, and the lower end of the is lowered, there is a communication between enlarged portion 39 of the bore through body 28 opens directly into chamber l2 of said tank. It will accordingly be seen that when valve member 48 is seated against its seat, a chamber 43 will be formed thereabove around the stem 4| and below restricted portion 28, but when member 48 the chamber l2 in tank l8 and chamber 43. The body 28 is ported at 44, which port communicates between chamber 43 and the atmosphere, hence when valve 48 is open, the chamber [2 is open to the atmosphere, but otherwise it is closed,

The valve 33 and valve member 43 are so positioned at the ends of stem 4| that upon the closing of valve 33, the member 48 will open, and vice versa.

The stem 4! is hollow from its lower end to A a point below the valve 33, thus providing a passageway 45 therein that opens at its lower end into an enlarged lower end 46 of the bore. 42,

said enlargement being formed in the valve member 48. The upper end of passageway 45 communicates with the chamber 35 by a lateral port 41 in the stem 4|, whichport 41 is below the valve element 33.

In the side walls of enlargedportion 45 is a row of openings 48 and below said row, the valve 48 is provided with a' lower end wall 43 formed with an opening in which is flexibly securedthe upper end of a rod 58 depending therefrom.

The upper end of rod 58 is formed with a pair, of vertically spaced collars 5|, 52, between which is the margin of the opening in the lower end wall 49 of valve member 48. One side of said opening is slotted out, as'at 53 to permit lateral insertion of the upper collar 5| into the opening, after which the sides of the outer end of the slot may be slightly swayed toward each other to prevent withdrawal of the collar.

A collar 53 is secured on rod 58 at a point spaced below the valve 48 a relatively short distance and another collar 54 is secured at the lower end of said rod, said latter and terminating a short distance above partition ll. Between collars 53, 54 is an annular hollow float 55, the central pas sageway 56 through said float freely passing the rod so as to permit the float to freely rise and fall with the rise and fall of liquid in chamber i2. The length of passageway 55 is such as to prevent any possibility of the float gripping the rod 58 to any appreciable degree should the float duit 26 and chamber I2, and opening 2,2e"r,492 l The strip forming each coil is inclined transflcient to permit the rod to swing slightly to com- 1 pensate for any tendency of the axis of the passageway 56 to become disaligned with the axis of rod 50. Also the outer lateral sides of float 55 are spaced from the sides of tank ill a sumcient distance to prevent any scraping of the float along the sides of the tank,

The operation of the float and valve device l5,

including the parts in the latter, is as follows:

- Upon the rise in the level of a liquid in chamber i2, the float will be raised until it strikes collar 53, at which time it'wili lift the valves 33, 43, opening the former and closing the latter, thus establishing a communication between gas conduit 26 and chamber l2. Assuming that the valves 33, 40 will remain inthe above position, unless forceably changed, upon lowering offloat 55 the latter will strike lower collar 54, thus closing the valve 33 and opening: the valve 40, and thereby closing the communicationbetween conthe chamber l2 to the atmosphere through port the pressure of gas in chamber 40 is suflicient to overcome the weight of the valves 34, 44, and stem 4|, together with rod 53 and the collars therein (by reason of the relatively greaterarea of valve 40 exposed to the pressure in chamber l2) the valves 33, 40 will remain in a position with valve 4!) closed, until the falling float positively pulls the valve 40 open.

The cooling coils of my invention are best shown in Figs. -3 to 8 while the coils are shown adjacent opposite upper corners in a refrigerator car or vehicle, they may, of course, be positioned in any enclosed area, whether in a' steamship,- or in a storage room.

Each of these coils comprises a pair of opposed, elongated sheets 60 of suitable rustless metal, formed with complementary grooves orchannels 6| with their concave sides opposed so as to provide spaced passageways 62 extending longitudinally of the sheet. The corresponding edges of the sheets are welding or the equivalent, so as to be leak-proof at the 80865, and between the said passageways,

a 44. Since l2 against valve preferably secured together, as by versely of its length with the high edge adjacent the roof 61 of the car and the low edge adjacent the adjacent side 58 of the car at the corner thereof. The high and low edges are spacedfrom the roof and side, respectively, and brackets or hangers 63 support the strips in position.

Spaced below each coil is an elongated drip panl0, inclined similarly to the coil adjacent thereto, but also slightly inclined longitudinally from opposite ends toward a low point where a drain pipe H (Fig. 3) is provided to draw any moisture of condensation dropping from the'coii thereabove. These pans are also spaced from the side of the car adjacent thereto. The form of the coils and pans and their relation to each otherand to the car sides and roof, form flues l2, 13 above and below the strip forming the coil, which flues facilitate the formation of the desired air currents in the car for most efficiently cooling the area therein, as best indicated by the arrows in Fig. 4. I

In Fig. 7 I show a modified form of passageway |l formed in sheet metal strips, insteadof the cylindrical form illustrated in Fig. 6. This sheet metal coils to the far end of the latter I relative to the tanks I, I0, is foundto be highly length of the car. There may be a separate tank l and tankcar, with a pipe 20 extending from each tank over one of the strips to theend remote from the tankfor supplying the liquid refrigerant to the passageways 82 at said end. In the drawings there are four passageways between the metal sheets GI, and an inlet manifold for each pair connecting with each pair of passageways (Fig. 8). The refrigerant then returns through passageways 32 toward the tanks and simflar outlet manifolds 36 connect with pipe 22 extending to tank III, the thermostatic valve 23 being in pipe 22. e t

ill for each strip at one end of the desirable from the standpoint of a control in the temperature within the car, since the cold refrigerant flowing through this pipe before being I spread over the area of the coils, functions to lower the temperature of the air before the larger heat transfer surfaces become effective. Supporting brackets may support the pipe 20 spaced above the cooling coil, as best indicated in Fig. 5. It has been found that with this arrangement in conjunction with the particular form of cooling coil the circulating system as described, the temperature of the air within the car is maintained substantially uniform from end to end of the car, and this temperature is maintained within a range of only several degrees, which is phenomenal in theme of 'solid CO2 as the primary cooling means. Heret-ofore the cooling has been spotty," that is, one end of the car may be closed and chamber l0, chamber 5, and the cooling coil with interconnecting pipes carries a conventional liquid refrigerant having a low freezing point, and the tank I contains the solid C02. The float '55 is at the lower end of its movement in chamber. l2 and valve 33 is closed while valve 40 is in open position. With this condition existing, the CO2 gas from tank I, at the predetermined pressure of say 6 lbs. per square inch, is eifective on the body of the refrigerant in chamber I3 and is also effective in chamber 35 over the valve 33, while the chamber I2 is vented to the atmosphere. Now assuming that the temperature of the air in the car rises sufllciently to cause the thermostatic valve 23 to open. It will be seen that upon the opening of said valve 23, the liquid refrigerant is forced through the chamber and cooling call into chamber l2, causing the float 55 to move upwardly on rod 53 until it engages collar 53 and lifts the valves 33, 40, thus opening valve 33 and closing valve 40. This opening of the valves is a quick opening since the pressure of gas on valve 33 must be overcome as well asthe force of gravity. As soon 'as the valve 33 is opened and valve 40 is closed, the pressures in through establishment of communication between chamber 35 (above valve 33) and chamber l2, and, the liquid in chamber I! will flow by gravity into chamber I3, thus lowering the float 55. Valve 40 will remain closed and valve 33 open until float 55 strikes collar 54 on rod 50, by reason of the greater exposed area on valve I being subjected to the pressure of gas in cham-' ber l2 than is above, the valve. The float upon encountering collar 54 causes the valve 40 to open and valve 33 to close, and the cycle is repeated so long as valve 23 is open. It is manifest that the control device I5 is operative at any time valve 23 is opened irrespective of the arrangement of the elements in said'device l5, and irrespective of the position of the float 55 in chamber I2. Also there are no springs to weaken, or'to depend upon, and no mercury or other variable medium than the gas the liquid refrigerant is relied upon for operation of the system.

Having described my invention, I claim:

1. In a refrigeration system in which there is a tank of solid CO2, a cooling coil, a control chamber, and a passageway in heat exchange relationship with the solid CO2 in said tank; said coolchambers l2, l3 are equalized communication between said upper compartment and said lower compartment. 1

3. 111 a refrigeration system in which there is a tank ofsolid C02,}; cooling coil, a control.-

chamber, and a passageway in heat exchange relationship with the solid CO2 in said tank; said cooling coil, control chamber and passageway being connected in series to form an endless conduit for a liquid refrigeranta CC gas pressure line communicating between said tank and chamber providing for gas pressure in said chamber for causing a periodic circulation of theliquid refrigerant through said conduit under influence of said gas pressure, control means for said gas comprising a valve body in said line provided with a single, movable valve element therein, ducts in said body and element for said gas controlled by movement of said element and aring coil, control chamber and passageway being connected in series to form an endless conduit for a liquid refrigerant, a C02 gas pressure line communicating between said tank and chamber providing for gas pressure'in said chamber for causing periodic circulation of the liquid refrigerant through said conduit under influence of said gas pressure, control means for said gas comprising a valve body in said line provided. with a single, movable valve element therein, ducts in said body' for said gas controlled by movement of said element and arranged and adapted to establish gas communication between said tank and chamber, and the venting of gas in said chamber to the atmosphere, alternately upon movement of said valve element between two predetermined positions on said body, afloat supported on the liquid refrigerant in said chamber responsive for movement between two predeter-' mined levels of the liquid refrigerant in said chamber, separate spaced means secured to-said valve element positioned for engagement by said float at said levels for moving said valve element to one or the other of said two positions according to the level of the liquid in said chamber.

2. In a construction as defined in claim 1, a by-passageway communicating between said gas line and said chamber open at all timesfor-communicating between said chamber and tank, a

single partition in said chamber dividing said chamber into an upper and a lower compartment only, said by-passageway communicating directly with said lower compartment, and said control means communicating directly with said upper compartment, said cooling coil communicating directly with said upper compartment, a pipe communicating between said tank and said lower compartment, and an open-ended tube extending from said partition to the point adjacent the lower end of said lower compartment establishing ranged and adapted to establish gas communication between said tank and chamber, and the venting of gas in said chamber to the atmos phere, alternately, upon movement of said valve element between two predetermined positions in said body, a float supportedon. the liquid refrigerant in said chamber responsive for movement between two predetermined levels of the liquid refrigerant in said chamber, an extension from said valve element vertically extending relatively loosely through said float for permitting relative movement between the extension and float upon said movement of the float, float engaging members secured on said extension above and below said float adjacent said predetermined levels in positions to be engaged by said float at said levels for actuating said valve between said two positions.

4. In a construction as defined in claim 2, said valve body having a straight bore therethrough and a pair of valve seats at opposite ends of said bore, said, valve element comprising a stem slidably fitted in said bore for'recip'rocation, a pair of members at opposite ends of said stem adapted to alternately engage said seats, enlarged chambers adjacent opposite ends of said bore, said gas line communicating between said tank and one of said enlarged chambers, the opposite chamber communicating with the control chamber, a port communicating between said opposite chamber and the atmosphere when said valve element is in one position at one end of its movement, and

- a passageway through said stem communicating between said gas pressure line and control chamber when said valve is in its other position at the other end of its movement.

5. In a refrigeration system including a tank for solid CO2, a cooling coil for a liquid refrigerant, a passageway through said tank in heat relationship with CO2 in said tank having an inlet and an' outlet with the outlet communicating with one end of said'cooling coil; liquid circulatingmeans for circulating liquid refrigerant through saidp'assageway and to said cooling coil and back'to said inlet, said circulating means comprising a single control chamber having a I partment, said bottom comprising the lower end of said chamber, a'check valve in said tube permitting flow of liquid refrigerant from said upper compartment to said lower compartment, a gas line leading from said tank to the upper portion of said lower compartment open at all times for conducting gas under pressure to said lower compartment, control valve means in the top of said upper compartment and a by-pass communicating between said valve means and'said gas line, a vent to the atmosphere communicating with said valve means; said valve means including a movable valve element, ducts associated with said valve means arranged and adapted to be con trolled by movement of said valve element for alternately establishing balanced and unbalanced gas pressures in said upper and lower compartments for intermittently forcing said liquid 'refrigerant from said chamber through said passageway and cooling coil and back to said cham-- her, and a float in said upper compartment supported on liquid refrigerant in said compartment fioatingly connected with said valve element for causing movement of said valve upon raising and lowering of the level of the liquid refrigerant in said compartment.

6. In a refrigeration system in which there is a tank of solid CO1, a cooling coil, a control chamber, and a passageway in heat exchange relationship with the solid CO: in said tank; said cooling coil, control chamber and passageway being connected in series to form an endless conduit for a liquid refrigerant, the lower portionof said tank, including the sides and bottom thereof, having double walls with the space between said walls forming said passageway, and

a helical spacer between the double side walls extending around the tank whereby the portion of said passageway formed by said double side walls is substantially helical in form, an inlet at the upper end of the helical portion of the passageway in communication with the said control chamber, and an outlet to the space between the double bottom of the tank communicating with one end or said cooling coil and the opposite end of said cooling coil communicating with said control chamber.

' 'LIn a construction as defined in claim 6, a gas pressure line communicating between said tank and control chamber providing CO: gas under pressure to said control chamber for providing power means to cause circulation of the liquid refrigerant through said endless conduit.

8. In a refrigerating car, container means at one end of said car for solid 00:, a circulating system for a liquid refrigerant including a cooling coil extending'lengthwise of the car along and spaced the upper corner .of the car defined by the juncture of the top with one lateral side of the car, said cooling coil comprising a flattened elongated conduit having one '01 its elongated edges adjacent the top of the car and the other elongated edge adjacent the said lateral side of the car for forming a passageway between the said upper corner of the car for passing the convec'tion currents caused by cooling of the air by said conduit. and a flattened elongated drip pan extending below said conduit and spaced therefrom forming a second passageway for such currents between said conduit and pen, a passageway in heat exchange relationship with the solid CO2 to be held in said container, the opposite ends of said conduit communicating with said passageway for completing the circulating system for said liquid refrigerant, and means in said system actuated by CO: gas from said container and by the liquid refrigerant in said system for causing the liquid refrigerant to circulate in said system.

9. In a refrigerator car, a cooling coil, com-i prising a pair of flattened sheets formed with.

opposedly disposed, elongated grooves providing passageways for the liquid refrigerant, said coil being positioned longitudinally of said car adjacent the roof {and one of the side walls of said car, and extending slantingly downward in a transverse direction toward said side wall.

10. In a refrigerator car as defined in claim 9, another of said cooling coils, positioned longitudinally of said car adjacent the roof and. the other of the side walls of said car, and extending slantingly downward in a transverse direction toward the other of the said sidewalls.

HARRY A. B. BROWN. 

